Nowadays a plurality of combination devices having both a hard disk drive (HDD) and a drive for recordable optical media, e.g. a recording drive for digital versatile disks (DVD), have become available on the market. Often these combination device are equipped with two or more inputs, such as an analog and a digital tuner, USB or IEEE1394 interfaces etc. The inputs are usually connected to a digital a/v compressor such as an MPEG encoder for either performing MPEG encoding and adding the navigation packs (NAV Packs) needed for DVD recording, or for transcoding a received transport stream (TS) into a program stream (PS) including such NAV Packs. This means that despite the presence of two different recording devices only the signal of one of the sources can be recorded at a time. One possibility to overcome this limitation is to provide an additional MPEG encoder IC. However, this solution is very costly and consequently not feasible for consumer devices. A cheaper solution is desirable.
US 2002/092021 discloses a digital video recorder with enhanced features. The video recorder is capable of simultaneously recording multiple a/v input signals, e.g. on hard disks or optical disks. For recording the received input a/v signals are transcoded, if necessary, by a decoder/decrypter capable of simultaneously handling a plurality of input streams.
EP 1 213 920 discloses an apparatus for simultaneously recording multiple digital a/v input signals. For recording the received input a/v signals are encoded. The apparatus uses an MPEG encoder capable of simultaneously encoding at least two a/v input signals.
US 2003/228126 discloses a multiple programmable video recorder capable of receiving and recording at least two input a/v signals. Theses signals are encoded/transcoded, if necessary, and stored on a hard disk in an interleaved manner. For each received a/v input signal a dedicated encoder is provided.
In the following an a/v (input) signal is to be understood as an analog or digital signal including audio and/or video information, whereby in case of a digital signal this signal may either be compressed or non-compressed.